4.0

Great book overall but it took me literally a decade to finish because of all the detailed information (and this book itself is already super thick!!!). I'm pretty sure that I'll re-read this book over and over again.
This one could be best served as a reference book, something that you read after finishing the main stories to find more easter eggs. All Sherlock Holmes stories were arranged chronologically, each story is covered by around 10 to 20 pages with original illustration. It talked about background stories, some hints that were not explained well enough in the main stories, Holmes's reasoning and etc. In some parts, it provided comparison between the stories which gives reader a more systematic thinking of how stories are related. A really enjoyable read.